buffum



UNITED sTATEs PATENT OEETOE. f

A. B UFEUM, OF BROOKLYN,r AND D, RUEEUM, OENEw YORK, N. Y.L y

ROTARY ENGINE.

specineatien of Letters Patentk Naas/is, dated octoberao, 1847.V

, the following t`Q be a full and exact descrip-g tion, reference being had to the accompany-gy ing drawings, making a part of this speciii-. cation, the same being a vertical view of theg' interior having one of the end plates removed.

The following description applies to ani engine six inches diameter yand ktwo inches,

deep, but the invention is equally applicable' to engines of all sizes, and for any extent of? power;

The cylinder marked A, A, is six inches diameter and two inches deep in the iclear. On the sides of the cylinder opposite to each: other are two projections B, B, called valve` chambers, adapted to the admission of steam, and to the size and form of the valves. The;v space included in the valve chambers is Open to the interior of the cylinder, except as partially or wholly closed by the position of the valves. The entrance of steam is to the: valve chambers, directly yback of the valve, ati C. The valve chamber is itted with packing so as to preventthe entrance of steam tog the cylinder when the valves are closed. The;y ends of the cylinder are covered with even plates, secured by bolts, and made steamz;v

tight. There are two escape holes D, D, in one, or in each of the end plates, located in; the open vacuum space G, between the outer surface Of the central portion of the re-1l volver, and the circle of the inner surface of;

the inclosing cylinder; their size and form as shown in the drawing Fig.y 2, being `adapted to the space allowed them by the form and movements of ythe revolver and,V valves, so as to give free escape for the ex` pended steam. rIvlhese holes are always open,2

except when covered by the ellipsis ofthe revolver passing over them; and there being four of them, (when made in each end plate) and all opened to the steam by'thepassing;

of the ellipsis of the revolver twice 1n every revolution, constitutes them an important; improvement in the rotary steam engine, in' combination with a revolver of any form ad; mitting of their use. The revolver E is six inches in diameter in one directionyand two` ,at `Z with a radius `one and eight-"tenths lline, witha radiusof three and 4three tenths L p volver.

and three. tenths inches, ,at the' @einer in the other direction. Its form is represented `in 'the'drawing by the following process; viz, .beginning with two straight'lines crossing `each otherl at the center at right angles, No.

l, No. l, called the right line, No. 2, No. `2,

Ythe cross line. On the left hand sideof'the rlght line, three inches from the center, we

mark the point circle 3, this circle is'three tenths of an inchY long, vand has its radial@ center at. the main center at a, Thenrfrom the left hand end of the point circle we draw a straight line N o. 4, to the main center, then from a radial center on this line at b, with a radius six tenths of an inch, we-.marke the-valve openingcircle 5. ,Then wediaw the straight line No.6, from the radial'centerfof circle 5 Vat c, on the cross line, two andkseven tenths inches from the main center.l Then with a radialccenter on this line inches, we mark the valve 'falling circle y7. Then Afrom a radialcenter` at e,on the cross inches, commencing at'the other end of the, right line, we mark the improvedvalve clos- ,ing circle I. Then from a radial center at f i :f i

onerandtwo 4tent-hs inches from the'extremity of thevcircle 8,A onl a direct line toward its radial center,.with a radius one and two Itenths inches, wejmark the valve lifting cir- `cle Then kwith a radius of three inclflSV havlng a radial center at g, equal .distance fromkthe central p oint of circles 7 ,and 9,. we`v mark the connecting curve l0, uniting the completes the form of one side lof the re Then by the ksame procesa-*commencing at the rvother. end ofthe right line, we mark the same circles and curves on the opposite side of the right line, andl so complete the form of the revolver. That portion of the revolver marked by the connecting curves 10,v we call the central portion,

while all the portion which extends more .71.001 than one and lthree twentieths of an inch y from thej center, we call the ellipsis p The valve closing circle 8, being drawn from a radial center on the cross line No. 2,

on the opposite side of the right line No. l, .105 lhas a peculiar eccentric movement, which imparts to a regularly curved gate valve, as it presses' it toward its chamber, such a movement and consequent position, that while the point formed by the junction of Y 9er circles 7, and 9, in a concave formrwhich 'valve .closing circle, maybe ata greater or less distancefrom themain'center, and its radius proportionally increased or dimin? ished ;which increase or diminution, will determine the'requisite curve of the face of the volver and the gate valve, during the pas- A ward barrier to the shown by Fig. l,

tenths inches.-

adapted curve of the valve, presenting itself i on the line of the circle of the inner surface of the cylinders,- and consequently supplying. an unbroken bearing surface, constituting'a leading barrier to the passage of steam;` while at Ythe same time, the 'opening edgev of the valve, continues in contact with the surface of the revolver, constituting a backpassage of steam, as

The design of the novel form givento the revolver, by the other circles and the` con-` necting burners, is, to effect the combination of a well graduated movement of the valves,

with alarge space between the surface of the revolver and the inner surface of the inclos-` `larger space for the escape holes through which the expended steam passesl off. All

the circles andcurves however, admit of various' modifications; the radialcenter of the valve, in orlder to produce the specified move-v are tted withpacking'4 to run steam tight, between the even platesl which cover the ends. of the cylinder. l i

The valves, F, F, are `two curvedgates,

three and ,two-tenths inches Vbroad from the 'center of motion; two inches long,"and of varied thickness.l The force lof theyvalve is A curved by a sweep of a radius one'and siX-"` A bolt live tenths of ani inch diameter, passes through `the length of the Valve, at theI back edge, and throughl the plates which cover the valve chamber; constituting an axis on which the valve' turns in opening and shutting, as a door.

turns onits hinges. The valves are placed? `in the valve chamber with the face of thel valve at its aXis on a line with the circle of the inner surface of the cylinder, in such position, that they can open into the interiorv of'thecylinder, by the action of the steam pressing on them, when the position of the` revolver will admit of their doing so. As,

'the point of the revolver when in action,

approaches the valve which is before it, the valve closing circle coming in contact' with theopening edge of the valve, communicates to the'valve the requisite movement and consequent position, as it shuts the valve into its chamber, when no Vsteam can enter the cylinder; and at the same mo-4 ment, the escape holes being uncovered, by the passing of the ellipsis of the revolver, the expended steam passes freely off. Pack-- cate a rotary movement.

position.

revolver. See Fig. 1.

ing is used in all parts where itis necessary to make the engine steam tight.

To keep up a uniform power in the engine withoutV a fly wheel, two revolvers, either with one or two ellipses to each, may be placed on the same shaft, with two or four valves, so arranged, that when one revolver is at its dead point, the other will I.The engine may be placed directly on any shaft to which we desire to communi- :By the term gate valve we `mean a valve constructed and arranged to' turn on an axis, whereby it is secured in its proper By the term point ofthe revolver, we refer to the vpoint of junction of the valve closing and the point circles, No. 2, and No. 3, with the end of the right" line No. 1.

What we claim as our invention, and desire to secure by Letters Patent, is-

1. The peculiar relative position of the resage of the point of the revolver by the face of the valve; towit, the point of the revolver,

running in continuous contact with the face of the valve,l and the opening .edge of the valve, during the same time (as at all times,) continuing in contact with the surface ofthe 2. The concave, instead of the cylindric form ofthe central portion of the revolver, adapted to the application of a larger'quantity of steam to act on theleverage of the revolver, and at the same time, admitting such breadth to the ellipsis of the revolver, as to secure a verygradualandfeasy movement to `the valves, andalso allowinga more free escape for .the expended steam. Seev Fig. 2.

3. The location of the escape holes, in the open vacuum space G, between, the `outer surface of the central portion of the revolver, and thel circle of the inner surface of the inclosing cylinder,"in the plates which cover the ends ofthe cylinder, in combination with the revolver herein described.

New York, Sept. 27, 1847.

' ARNOLD BUFFUM.

y DAVID BUFFUM. fSigned, by Arnold Buum in presence o CHARLES H. HEDGES, A. E. FREELAND.

f By David Buffum in presence of- Trios. BUFFUM, n `L GEORGE ALDRroH. l' 

